Pricing Forwards and Futures

Transcription

1 Pricing Forwards and Futures Peter Ritchken Peter Ritchken Forwards and Futures Prices 1 You will learn Objectives how to price a forward contract how to price a futures contract the relationship between futures and forward prices the relationship between futures prices and expected prices in the future. You will use arbitrage relationships become familiar with the cost of carry model learn how to identify mispriced contracts. Peter Ritchken Forwards and Futures Prices 2 Ritchken 1

2 Forward Curves Forward Prices are linked to Current Spot prices. The forward price for immediate delivery is the spot price. Clearly, the forward price for delivery tomorrow should be close to todays spot price. The forward price for delivery in a year may be further disconnected from the current spot price. The forward price for delivery in 5 years may be even further removed from the current spot price. Peter Ritchken Forwards and Futures Prices 3 Forward Prices of West Texas Intermediate Crude Oil. A Contango Market Forward Prices Time to Expiration Peter Ritchken Forwards and Futures Prices 4 Ritchken 2

3 Forward Prices of West Texas Intermediate Crude Oil. A Backwardation Market Forward Prices Time to Expiration Peter Ritchken Forwards and Futures Prices 5 Forward Prices of West Texas Intermediate Crude Oil. Short term Backwardation/Long term Contango Forward Prices Time to Expiration Peter Ritchken Forwards and Futures Prices 6 Ritchken 3

4 Forward Prices of West Texas Intermediate Crude Oil. Mixed Contango/Backwardation Forward Curve Forward Prices Time to Expiration Peter Ritchken Forwards and Futures Prices 7 Forward Prices of Heating Oil. Peaks in Winter and lows in Summer. Forward Prices Time to Expiration Peter Ritchken Forwards and Futures Prices 8 Ritchken 4

5 Forward Prices of Electricity. Peaks in Winter and Summer with lows in winter and fall. Forward Prices Time to Expiration Peter Ritchken Forwards and Futures Prices 9 What determines the term structure of forward prices? How can we establish the fair forward price curve? Does the forward curve provide a window into the future? Do forward prices predict future expected spot prices? What can we learn from forward prices? Do futures prices equal forward prices? What can we learn from futures prices? Peter Ritchken Forwards and Futures Prices 10 Ritchken 5

6 Forward and Futures Prices We make the following assumptions: No delivery options. Interest rates are constant. This means there is only one grade to be delivered at one location at one date. S(0) is the underlying price. F(0) is the forward price and T is the date for delivery. Peter Ritchken Forwards and Futures Prices 11 The Value of a Forward Contract At date 0: V(0) = 0 At date T: V(T) = S(T) - FO(0) What about V(t)? Peter Ritchken Forwards and Futures Prices 12 Ritchken 6

7 Determining V(t) Value at 0 Value at t Value at T Buy Forward at date 0 0 V(t) S(T)-F(0) Sell a forward at date t - 0 -(S(T)-F(t)) Value of Strategy V(t) F(t) F(0) Peter Ritchken Forwards and Futures Prices 13 What is V(t)? V(t) = Present Value of F(t) - F(0). BUT F(t) and F(0) are known at date t. Hence the payout is certain. Hence we have: V(t) = exp(-r(t-t))[f(t)-f(0)] Peter Ritchken Forwards and Futures Prices 14 Ritchken 7

8 Property The value of a forward contract at date t, is the change in its price, discounted by the time remaining to the settlement date. Futures contracts are marked to market. The value of a futures contract after being marked to market is zero. Peter Ritchken Forwards and Futures Prices 15 Property If interest rates are certain, forward prices equal futures prices. Is this result surprising to you? Peter Ritchken Forwards and Futures Prices 16 Ritchken 8

9 With One Day to Go Initial Value Final Value Long 1 forward 0 S(T) FO(T-1) Short 1 futures 0 -(S(T) FU(T-1) 0 FU(T-1)-FO(T-1) Peter Ritchken Forwards and Futures Prices 17 With Two Days to Go Initial Value Final Value Long 1 forward Short B(T-1,T) futures 0 [FO(T-1) FO(T-2)]B(T-1,T) 0 -[FU(T-1) FU(T-2)]B(T-1,T) 0 [FU(T-2)-FO(T-2)]B(T-1,T) Peter Ritchken Forwards and Futures Prices 18 Ritchken 9

10 With Three Days to Go Initial Value Final Value Long 1 forward Short B(T-1,T) futures 0 [FO(T-2) FO(T-3)]B(T-2,T) 0 -[FU(T-2) FU(T-3)]B(T-2,T) 0 [FU(T-3)-FO(T-3)]B(T-2,T) Peter Ritchken Forwards and Futures Prices 19 Example: Tailing the Hedge Little Genius sells a Forward Contract. Then hedges this exposure by taking a long position in x otherwise identical futures contracts. What should x be? With T years to go to expiration, the number of futures contracts to purchase is x = exp(-rt) The strategy is dynamic, since the number of futures to hold changes over time. ( Actually increases to 1 as T goes to 0) Peter Ritchken Forwards and Futures Prices 20 Ritchken 10

11 Example FO(0) = FU(0) = F(0) = 100 F(1) = 120; F(2) = 150; F(3) = 160 Profit on Forward: = 60 Profit on Futures : 20exp(r 2/365) +30exp(r 1/365) Peter Ritchken Forwards and Futures Prices 21 Example: Now Tail the Hedge. With 3 days to go: Buy N 3 = exp(-r 2/365) futures. With 2 days to go: Buy N 2 = exp(-r 1/365) futures. With 1 day to go: Buy N 1 = 1 futures. Profit on this strategy is 20N 3 e r2/ N 2 e r1/ = = 60 This is the payout of a forward. Peter Ritchken Forwards and Futures Prices 22 Ritchken 11

12 Property If futures prices are positively correlated with interest rates, then futures prices will exceed forward prices. If futures prices are negatively correlated with interest rates, then futures prices will be lower than forward prices. Peter Ritchken Forwards and Futures Prices 23 Proof For Positive Correlation. FU prices increase, the long wins and invests the proceeds at a high interest rate. FU prices decrease, the long looses, but finances the losses at a lower interest rate. Overall, the long in the futures contract has an advantage. The short will not like this, and will demand compensation in the form of a higher price. Peter Ritchken Forwards and Futures Prices 24 Ritchken 12

13 Pricing of Forward Contracts Consider an investment asset that provides no income and has no storage costs. (Gold) If the forward price, relative to the spot price, got very high, perhaps you would consider buying the gold and selling forward. If the forward price, relative to the spot price, got very low, perhaps you would consider buying the forward, and selling the asset short! Lets take a closer look at the restriction these trading schemes impose on fair prices. Peter Ritchken Forwards and Futures Prices 25 Pricing Forward Contracts Little Genius starts off with no funds. If they buy an asset, they must do so with borrowed money. We first consider the following strategy: Buy Gold, by borrowing funds. Sell a forward contract. At date T, deliver the gold for the forward price. Pay back the loan. Profit = F(0)- S(0)exp(rT) Peter Ritchken Forwards and Futures Prices 26 Ritchken 13

14 Cost of Carry Model Clearly if F(0) > S(0)exp(rT), then Little Genius would do this strategy. Starting with nothing they lock into a profit of F(0)-S(0)e rt >0! To avoid such riskless arbitrage, the highest the forward price could go to is S(0)e rt. F(0) < S(0)e rt. Peter Ritchken Forwards and Futures Prices 27 Reverse Cash and Carry: (In a Perfect Market) Note that profit from the startegy is known at date 0! If positive, Little Genius does the strategy! If negative, Little Genius does the opposite! That is LG buys the forward contract, and sells gold short. Selling short generates income which is put into riskless assets. Profit = S(0)exp(rT) - F(0) Peter Ritchken Forwards and Futures Prices 28 Ritchken 14

15 Reverse Cash and Carry: (In a Perfect Market) If Profit = S(0)exp(rT) - F(0) >0, Little Genius would make riskless arbitrage profits. Hence: S(0)e rt <F(0) That is, to avoid riskless arbitrage, the forward price must be bigger then the future value of a riskless loan of S(0) dollars. Hence: S(0)e rt < F(0) < S(0)e rt, Or F(0) = S(0)e rt Peter Ritchken Forwards and Futures Prices 29 Term Structure of Gold Futures Prices (In a Perfect Market) A Contango market for Gold! Futures Price F = S(0)e rt Maturity Peter Ritchken Forwards and Futures Prices 30 Ritchken 15

16 Arbitrage Restriction To avoid riskless arbitrage, the price of a forward contract on Gold is: F(0) = S(0)exp(rT) Peter Ritchken Forwards and Futures Prices 31 Example: S(0) = 400; F(0) = 450; T = 1 year; Simple Interest Rate = 10% per year. Borrow $400 for 1 year at 10% +400 Buy 1 ounce of Gold -400 Sell 1 forward contract 0 Net cash flow 0 Peter Ritchken Forwards and Futures Prices 32 Ritchken 16

17 After 1 year: Example (continued) Remove gold from storage and deliver: 450 Repay loan, including interest -440 Net Cash Flow = +$10 F (0) Initial Investment = $0. To avoid arbitrage free profits from this strategy: F(0) < 440 Peter Ritchken Forwards and Futures Prices 33 Example Cash and Carry with Market Imperfections S(0) = 400; F(0) = 450; Simple interest rate = 10%; Transaction Cost = 3% of spot. At Date 0: Sell Forward Contract Borrow $412 at 10% Buy 1oz. Of Gold Net Cash Outflow... 0 Peter Ritchken Forwards and Futures Prices 34 Ritchken 17

18 Cash and Carry with Market Imperfections (continued) At Date T: Remove Gold from Storage and Deliver Repay Loan Total Cash Flow Hence, F(0) < $ Peter Ritchken Forwards and Futures Prices 35 Reverse Cash and Carry with Market Imperfections S(0) = 400;F(0)=450;Interest Rate = 10% Transaction Cost = 3% At Date 0 Sell 1oz. gold short Receive 400(0.97)...$388 Invest proceeds at riskless rate...-$388 Net Cash Flow...$0 Peter Ritchken Forwards and Futures Prices 36 Ritchken 18

19 Reverse Cash and Carry with Market Imperfections (continued) At Date T: Accept loan proceeds [388(1.1)] Accept gold delivery Total Cash Flow Therefore, you would have arbitrage free profits if F(0) < $ Peter Ritchken Forwards and Futures Prices 37 Arbitrage Free Bounds Hence, to avoid riskless arbitrage: 426.8<F(0)<453.2 The size of the bounds increase with market imperfections. However, the actual size of the bounds are determined by the market players that face the least imperfections! Peter Ritchken Forwards and Futures Prices 38 Ritchken 19

20 Pricing Futures Contracts on Stocks S(0) = 100 d = $2 in 0.5 years. Interest = 10% simple. Forward contract is for 1 year At Date 0 Forward contract for 1 year. Borrow $ and Buy stock Peter Ritchken Forwards and Futures Prices 39 Pricing Futures Contracts on Stocks At Date t=0.5 Receive $2. Invest $2 at 10% per year At date T= 1 Collect proceeds from dividend...$2.10 Sell stock for forward price...f(0) Repay loan...-$110 Profit = F(0) Profit is positive if F(0) exceeds Peter Ritchken Forwards and Futures Prices 40 Ritchken 20

21 Futures Prices on Stock To avoid arbitrage opportunities theforward priceisboundedby: rt r( T t) F(0) S(0) e de F(0) S(0)[1 + rt] d[1 + r( T t)] Peter Ritchken Forwards and Futures Prices 41 Forward Prices on a Stock To avoid arbitrage opportunities the forward price of a stock is F(0) = S(0)exp(rT) - d exp(r(t-t)) F(0) = S(0)[1+rT] - d[1+r(t-t)] Peter Ritchken Forwards and Futures Prices 42 Ritchken 21

22 Futures Price on a Nondividend Paying Stock Does the futures curve provide any forecasting power for the future stock price? If the slope of the futures curve increases The prospects for the stock has improved? Interest Rates have increased? Peter Ritchken Forwards and Futures Prices 43 Stock Market Indices Time 0 Time t Shares Outstanding A B C Peter Ritchken Forwards and Futures Prices 44 Ritchken 22

23 Market Value Indices MV(0) = 150(50)+40(100)+10(500)=16500 MV(t) = 150(50)+80(100)+30(500)=30500 I(0) = 100 I(t) = I(0)[MV(t)/MV(0)] =100[30500/16500] = Peter Ritchken Forwards and Futures Prices 45 Price Weighted Index V(0) = [ ]/3 = V(t) = [ ]/3 = I(t) = [V(t)/V(0)]I(0) = [86.67/66.667]100 =130 Peter Ritchken Forwards and Futures Prices 46 Ritchken 23

24 Ritchken 24 Peter Ritchken Forwards and Futures Prices 47 Pricing Futures on Price Weighted Indices Stocks in the index are A and B. A pays a dividend of size d A at time t A. B pays a dividend of size d B at time t B. ) ( ) 0 ( ) 0 ( ] [ )] 0 ( ) 0 ( [ ) 0 ( ) 0 ( ) 0 ( ) 0 ( ) ( ) ( ) ( ) ( dividends FV e I F e d e d e S S F e d e S e d e S F rt t T r B t T r A rt B A t T r B rt B t T r A rt A B A B A = + + = + = Peter Ritchken Forwards and Futures Prices 48 Stock Index Arbitrage with a Value Weighted Index Price Shares Div Time to Div. A 40 1m days B 35 2m days C 25 2m - -

25 Example: Stock Index Arbitrage with Price Weighted Index Composition of Index: A= 40/ ( ) = 1/4 B = 7/16 C=5/16 I(0) = 400 Multiplier = 500 Each contract controls 400(500) = $200,000. Peter Ritchken Forwards and Futures Prices 49 Portfolio Composition: Stock Index Arbitrage (1/4 )(200,000) = $50,000 or 1,250 shares of A (7/16)(200,000) = $87,500 or 2,500 shares of B (5/16)(200,000) = $62,500 or 2,500 shares of C Peter Ritchken Forwards and Futures Prices 50 Ritchken 25

26 Stock Index Arbitrage Stock A B C Borrowed Funds Number Shares Dividend Income Received and Invested at 10% 50,000 87,500 62,500 1,250 2,500 2, Peter Ritchken Forwards and Futures Prices 51 Stock Index Arbitrage Amount owed = 200,000exp(0.10(30/365) = $201, less dividends and interest... -$1, Total =....$199,766 Theoretical Futures Price = 199,766/500 = Note, in this example I(0) = 400 Peter Ritchken Forwards and Futures Prices 52 Ritchken 26

27 Stock Index Futures Prices and Index Prices If Stock index futures prices are upward sloping as a function of maturity, then market participants are forecasting that the market will increase ( ie the sentiment is bullish) Is this true? Peter Ritchken Forwards and Futures Prices 53 Forward Contracts on FOREX Price of 1 British Pound is S(0) dollars. Strategy 1: Invest S(0) dollars at the risk free rate to obtain S(0)exp(r D T) dollars at date T. S(0) dollars grows to S(0)exp(r D T) dollars Peter Ritchken Forwards and Futures Prices 54 Ritchken 27

28 Strategy 2: Forward Contracts on FOREX Sell exp(r F T) forward contracts on the pound. Each contract gives the obligation to exchange 1 pound for F(0) dollars. Buy 1British pound. Invest in riskless rate in Britain to obtain exp(r F T) pounds. Deliver the pounds for exp(r F T) F(0) dollars. S(0) grows to exp(r F T) F(0) Peter Ritchken Forwards and Futures Prices 55 Forward Contracts on FOREX To avoid arbitrage opportunities: S(0)exp(r D T) = exp(r F T) F(0) or F(0) = S(0)exp[(r F -r D )T] Forward prices relate to spot prices depending on interest rate differentials. Peter Ritchken Forwards and Futures Prices 56 Ritchken 28

29 Pricing Futures Contracts on Dividend Paying Stocks Assume interest rate is r and storage costs are a fixed percent of the spot price. The underlying pays no dividends. F(0) = S(0)exp[(r+u)T] Now assume the underlying pays a continuous dividend yield, expressed as a percent of the price. Then F(0) = S(0)exp[(r+u-d)T] Peter Ritchken Forwards and Futures Prices 57 Pricing Futures Contracts on Dividend Paying Stocks F(0) = S(0)exp[(r+u-d)T] The spot price of the S&P500 index is The dividend yield is 3% per year. Interest rates are 5% continuously compounded. Storage costs are 0%. A one year futures contract should have a futures price of Then F(0) = S(0)e (r-d)t = 1000 e 0.02 = Peter Ritchken Forwards and Futures Prices 58 Ritchken 29

30 Forward Prices of a Property You can buy a property now for $100m. Alternatively, you can enter into a forward contract to purchase the property in two years time. The property has a maintenance fee that is 1% of the price. The property has buildings that provide rental income that is estimated at 6% of the price per year. The fair forward price of the property is 100e (r+u-d)t = 100e ( )2 = 100 million dollars. Peter Ritchken Forwards and Futures Prices 59 Futures Prices of Storable Commodities. Commodity forward contracts have two important features that are not present when the underlying is a financial asset. Storage Costs Convenience Yields Storage Costs Warehouse space, transportation costs, spoilage, insurance. We will represent these charges as a fraction of the market price of the commodity. If storage costs are 20%, this implies that the annualized storage costs are about 20% of the spot market price. Peter Ritchken Forwards and Futures Prices 60 Ritchken 30

31 Futures Prices of Storable Commodities. The convenience yield Unlike securities, commodities are usually consumed or used in a production process. Having a commodity on hand has value since it allows the production process to continue without disruptions. If the commodity is abundant then there is not much benefit from having it in storage. However, If the commodity is scarce, then having the commodity in inventory is very beneficial. One can view the potential benefit of having a commodity on hand as a yield, just like a continuous dividend yield. We express the convenience yield as a percent of the price in an annualized form Peter Ritchken Forwards and Futures Prices 61 Futures Prices of Storable Commodities. A 2% convenience yield means that having the item readily available comes at a cost that accrues at a rate of 2% of the current price of the commodity per year. Example: Spot price = 100; Interest Rate = 5%; Storage Cost = 8% Convenience Yield = 7%. Time to expiration is 1 year. F(0) = S(0) e (r+u-k)t = 100 e ( ) = Peter Ritchken Forwards and Futures Prices 62 Ritchken 31

32 Upper Bound for Commodity Forwards: The Cost of Carry Model If forward price is very high: Sell the forward contract Buy the commodity using borrowed funds. Pay the storage fees with borrowed funds Deliver the commodity for the forward price. Profit is: FO(0) S(0)e (r+u)t Clearly, to avoid riskless arbitrage: F0(0) < S(0)e (r+u)t Peter Ritchken Forwards and Futures Prices 63 Lower Bound for Commodity Forwards If the forward price was very low we would like to initiate the reverse cost of carry. In particular, we need to short sell the commodity. We must borrow the commodity from party, A, and then sell it. This deprives A from a convenience yield. A is giving up having inventory around to meet unexpected needs! Clearly A needs to be compensated for this. This compensation is the convenience yield, represented by k% per annum as a fraction of the commodity price Peter Ritchken Forwards and Futures Prices 64 Ritchken 32

33 Lower Bound for Commodity Forwards A does get to save the storage fees, represented by u% per annum as a fraction of the commodity price. So A requires a net compensation that accrues at the rate of k-u% If we borrow one unit now, we have to compensate A by providing e (k-u)t units at date T. Equivalently, for every e -(k-u)t units that we take today we owe 1 unit at date T. Peter Ritchken Forwards and Futures Prices 65 Lower Bound for Commodity Forwards So we go long 1 forward contract, and we borrow e - (k-u)t units, and sell them. At date T, we purchase 1 unit for the forward price, and return 1 unit to the borrower. The net profit is: Profit = [e -(k-u)t ]S(0)e rt FO(0) = S(0)e (r+u-k)t - FO(0) Profit if S(0)e (r+u-k)t > FO(0) Hence to avoid riskless arbitrage: FO(0) > S(0)e (r+u-k)t Peter Ritchken Forwards and Futures Prices 66 Ritchken 33

34 Commodity Forward Prices. S(0)e (r+u-k)t <FO(0) < S(0)e (r+u)t The upper bound is easy to obtain. The lower bound is a problem, since the convenience yield is not known. Forward prices on commodities can have such wide upper and lower bounds, that little can be said about these prices from arbitrage arguments alone! We need a deeper model. Peter Ritchken Forwards and Futures Prices 67 Bounds on Forward Prices Forward Price Upper Bound ( easy) Actual Prices Lower Bound (?) Maturity Peter Ritchken Forwards and Futures Prices 68 Ritchken 34

35 Interpreting the Convenience Yield Let k be the convenience yield. You can view this like a dividend yield, but it is not observable! Then, we will write: F(0) = S(0)exp[(r+u-k)T] When will k be large? When will k be small? Can k depend on the time horizon? ( ie. Different k values for different futures contracts.) Peter Ritchken Forwards and Futures Prices 69 The Implied Convenience Yield If the convenience yield was k%, then FO(0) = S(0)e (r+u-k)t In practice the forward prices are given. So we can imply out the average convenience yield over the period [0,T]. Peter Ritchken Forwards and Futures Prices 70 Ritchken 35

36 Example On April 1 st, S(0) = 1.96, u = 1%, r=9% Settle Date May July Sept Dec March Futures Price Upper Bound Implied k 16.13% 18.24% 21.28% 15.46% 13.96% Peter Ritchken Forwards and Futures Prices 71 Implied Convenience Yields Consider maturity s and t contracts with s<t FO t (0) = FO s (0)e (r+u-k)(t-s) Why is this true? We can imply out convenience yields over specific periods. Peter Ritchken Forwards and Futures Prices 72 Ritchken 36

37 Example (Continued) On April 1 st, S(0) = 1.96, u = 1%, r=9% Settle Date May July Sept Dec March Futures Price Upper Bound Implied k 16.13% 18.24% 21.28% 15.46% 13.96% Implied rates April-May 16.13% May July 19.29% July-Sept 25.83% Sept-Dec 5.74% Dec-Mar 10% Peter Ritchken Forwards and Futures Prices 73 Forward Prices, Spot Prices, and Forecasts Expect future prices to be high: Sellers will increase their inventories so as to capture the high prices. Buyers will want to buy more today. Buyers will demand more from sellers who prefer to sell less. These conflicting positions will drive spot prices up Price expectations are an important part of the formation of spot prices. With inventory, changes in future expectations have impact on current prices. Peter Ritchken Forwards and Futures Prices 74 Ritchken 37

38 Price Variations and Storage Issues As storage costs increase, the connections between expected future prices and current prices diminish. With high storage costs the alternative of holding inventories for future sale is less attractive than if storage costs are negligible. As storage costs increase, expectations of higher future prices will have less impact on current spot prices. As storage costs increase, the price variation over time in the forecasts increase. As storage costs increase, actual price variations over time increase. Peter Ritchken Forwards and Futures Prices 75 Example: Electricity Electricity is difficult to store. Expected price forecasts vary by the hour. Actual prices fluctuate widely. Cost of carry model and reverse cost of carry model do not hold. Peter Ritchken Forwards and Futures Prices 76 Ritchken 38

39 Spot Forecasts Versus Forward Prices What is the link between forward prices and expected spot prices for non storables? Peter Ritchken Forwards and Futures Prices 77 Futures Prices and Expected Future Spot Prices Suppose k is the expected return required by investors on an asset. (k = r + risk premium) We could invest Fexp(-rT) today to get S(T) at date T. How would you do this? Hence Fexp(-rT) = E[S(T)]exp[-kT] No systematic risk? Positive systematic risk? Negative systematic risk? Peter Ritchken Forwards and Futures Prices 78 Ritchken 39

40 Futures Price For Nonstorable Commodities E[S(T)] = 100 F(0) = 100 Perhaps a speculator would enter a forward contract at 90. Expect to make a $10 profit. What if F(0) = 99 The speculator expects to make $1, but risk. Futures prices may not be unbiased estimators of future spot prices. Peter Ritchken Forwards and Futures Prices 79 Normal Backwardation If all hedgers were SHORT, all speculators, LONG. Hedgers will pay a premium to reduce risk Speculators will require a premium to accept risk. F(0) < E[S(T)] This market is called normal backwardation. Peter Ritchken Forwards and Futures Prices 80 Ritchken 40

41 A Contango Market If all hedgers were LONG, all speculators, SHORT Hedgers will pay a premium to reduce risk Speculators will require a premium to accept risk. F(0) > E[S(T)] This market is known as CONTANGO. If F(0) = E[S(T)]= E[F(T)]. Futures prices are martingales Peter Ritchken Forwards and Futures Prices 81 Expected Spot Prices and Forward Prices The risk premium equals the difference in prices ( expected spot less forward), as a percentage of the forward. Price Spot Forecasts Forward Curve Maturity Peter Ritchken Forwards and Futures Prices 82 Ritchken 41

42 Risk Premiums Producers Perspective There is no theoretical reason for forward prices to act as an unbiased estimator of future expected prices. The risk premium may be positive or negative! The risk premium may start out big positive, say, and then decline to zero at the expiration date. The risk premium exists due to risk aversion. Producers (sellers) are generally risk averse. They may have debt obligations associated with their capital stock. They need stable cash flows. So, they may be willing to accept forward prices that are less than expected spot prices. Peter Ritchken Forwards and Futures Prices 83 Risk Premiums Consumers Perspective Buyers may also have a desire to avoid price risk. They may prefer to pay a premium for price security. This implies that forwards might be higher than expected prices and risk premiums would be negative. Relative desire for price security between these groups that will determine the sign of the risk premium. Peter Ritchken Forwards and Futures Prices 84 Ritchken 42

43 Speculators Speculators are also present. They are concerned about forward prices relative to expected future prices. Does the strategy of buying forward and then selling at spot prices increase the total risks of a well diversified portfolio? Yes-speculators need a positive risk premium. Forward will be below expected prices Peter Ritchken Forwards and Futures Prices 85 The Market Price of Risk The Risk Premium can be decomposed into two parts: Volatility ( or the amount of risk) The price per unit of risk. The price per unit of risk is called the market price of risk. Estimating the market price of electricity risk is difficult. Peter Ritchken Forwards and Futures Prices 86 Ritchken 43

44 Summary Forward prices and futures prices are close to each other. Futures give cash flows right away, forward do not. This has hedging implications. For securities, the cost of carry model and the reverse cost of carry model gives us forward prices. Market imperfections lead to bounds on prices. For commodities storage costs and convenience yields must be considered. The upper bound is easily computable, but the lower bound depends on the convenience yield. Peter Ritchken Forwards and Futures Prices 87 Summary For commodity forwards and futures there is some flexibility as to where the forward prices can fall. That is, arbitrage alone, cannot identify the theoretical price, and we need richer models. When storage costs are high, forward prices and indeed spot prices and their forecasts can be more volatile. Cheap storage has the effects of smoothing prices over time. Implied convenience yields can be extracted from futures prices and can be informative. Peter Ritchken Forwards and Futures Prices 88 Ritchken 44

45 Summary In general commodity forward curves will reflect seasonality since the convenience yields will fluctuate according to aggregate inventory levels. Electricity is not readily storable, and forward prices here represent a challenge. For non storables, forward prices are linked to expected future spot prices. However, they are not unbiased estimators. Peter Ritchken Forwards and Futures Prices 89 Summary For electricity prices, we may expect spikes and other weird phenomenon. For storables, as future expectations change, a ripple effect is felt through to current prices. Price changes should therefore be more smooth. If storage costs increase, then price volatility should increase. Peter Ritchken Forwards and Futures Prices 90 Ritchken 45